This program involves development and evaluation of new radiologic technology. Improvements of the sensitivity of fluorescent excitation analysis (FEA) are being made by pulse rise-time selection and the addition of an external photon anticoincidence shield. A high resolution germanium camera is being evaluated with various radioisotopes of clinical interest. The camera is also being used to help to understand the nuclear medicine imaging process. Room temperature semiconductors are being evaluated for nuclear medicine imaging. Research is concentrating on improving the spectral response of the detectors through the use of appropriate electronics and on evaluating small imaging modules. Tissues in normal and diseased live rats are being imaged by nuclear magnetic resonance (NMR) imaging, to obtain NMR signatures and correlate these with in vitro measurements of tissue compartments.